Mostly Biomathematics Lunchtime Seminar
Quantum Calculations on Potassium Ion Channels
Speaker: Michael E. Green, Department of Chemistry and Biochemistry, City College of New York
Location: Warren Weaver Hall 1314
Date: Tuesday, November 19, 2019, 12:30 p.m.
Synopsis:
Potassium channels, along with sodium and calcium channels, are required for a vast number of physiological functions, including the nerve impulse. Quantum calculations on the Kv1.2 potassium channel suggest that gating of the channel involves proton and side chain rearrangements in the voltage sensing domain (VSD) but not large scale motion of a transmembrane segment (the S4 segment of the VSD), which is considered to be required in standard models of gating. The results of these calculations will be presented, including charges on key groups from NBO calculations, which change as protons rearrange. We show reasons for reinterpreting the evidence for standard gating models. There will also be some consideration of the results of calculations of the transition of the ion in the pore of the channel as the ion transfers into the selectivity filter. These results are in reasonable agreement with certain relevant experimental X-ray structures.